I suggest you ...

list more than 5 contacts when you first start typing a new message

When you go to draft a new message and you want to begin typing a name of a contact, more than 5 contacts meeting the search as you type it should appear in the list with an option to scroll through more. limiting search result to 5 entries is insufficient when you don't remember last names....

When you start typing a name or phone number in a new message window, the drop down list only shows the first 5 matches. That is not nearly enough.

For example, If I'm searching for Bob Smith, I have many more than 5 "Bob"s in my contacts, and many more than 5 "Smith"s. Other apps allow me to scroll through ALL the matching contacts.

And if a contact is stored as Last Name, First Name (which most of mine are, due to gmail's idiosyncrasies), typing the comma tells MightyText I'm done entering that contact, and moves on, not allowing me to search further. Far too often, I have to go to my gmail contacts page to find the number and cut and paste it into MightyText.

It would also be helpful to only have mobile numbers displayed. When I'm texting, I don't need to have home, work, fax, & other numbers displayed.